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Fancy New Lids for Nuclear Waste Casks, As Contents Get Hotter

The nuclear industry has about doubled the potency of nuclear fuel rods since 1970, allowing plants to stay online longer between refueling outages and to produce less waste. But the dry casks holding spent fuel rods across the United States have not evolved along with their increasingly radioactive contents.

Uncertain what’s happening inside dry casks, the Department of Energy and the industry’s Electric Power Research Institute are embarking on a four-year, $16 million project to develop instrumented lids that can report on the status of the spent rods inside.

“The project will enable us to equip a dry storage cask lid with advanced instrumentation so we can collect gas samples and monitor temperature and other variables while the fuel is cooling down,” said Neil Wilmshurst, EPRI’s vice president and chief nuclear officer.

High burnup fuel rods stay hotter longer, emit more radioactivity, and may become brittle, scientists suspect, as the cladding that holds them together endures greater stresses. That could be a problem if the time comes to transport spent fuel from reactor sites to a central storage facility.

“With the prospect looming for extended long term storage – possibly over multiple decades – and deferred transport,” maintaining the condition and performance of dry casks “is now a necessity that requires immediate attention,” according to a paper by scientists at Argonne National Laboratory and the Department of Energy.

Nuclear engineers have long known of increased risks from high burn-up fuels, but scientists at Argonne have been sounding the alarm about storage dangers in recent years after their research (pdf) showed high burn-up fuels may result in fuel rods becoming more brittle over time.

If the U.S. finds a place for its nuclear waste to go, some fuel assemblies will have to be removed from casks and transferred to transportation packs, a dangerous enough task without the prospect of fuel rods ruptured or crumbling.

“Such retrieval and reloading, either in air or in the used-fuel storage pool, requires that both the fuel rods and assemblies possess adequate structural integrity,” Argonne scientists wrote in 2011. “Any canisters and casks that experienced significant degradation during extended storage may also face the need of retrieval of used fuel assemblies for a cask replacement.”

If the United States doesn’t find a place for its nuclear waste to go, and it remains in casks across the country, scientists need a better idea what’s cooking inside.

“Because a disposal path is lacking in the United States at present, extended cask storage, up to multiple decades, may be required. Ensuring the structural integrity of the used fuel assemblies, the canisters, and other structures and components in the DCSS [dry cask storage system] that are important to safety and ensuring used fuel retrievability over an extended period is imperative.”

The current technology (Image: Argonne National Laboratory)

In April, DOE announced a $15.8 million investment in dry cask storage research, led by EPRI, with the industry kicking in about 20 percent of the cost. Last week EPRI revealed some details: From 2014 to 2016, EPRI will design, license, and build a new type of dry storage cask with instruments built into the lid to monitor what’s happening with the spent fuel inside. In mid-2017 they plan to load spent fuel rods into the prototype cask.

“The demonstration will enable researchers to evaluate the performance of the cask system and ensure the integrity of the fuel,” according to EPRI.

At a 2011 conference, Argonne and DOE scientists proposed modifying sensors that are already used to monitor other nuclear materials during packaging and shipping.

“The current built-in sensor suite consists of seal, temperature, humidity, shock, and radiation sensors” they said. “Other sensors can be easily added as needed. The system can promptly generate alarms when any of the sensor thresholds are violated.”

To monitor the interior of dry casks, the current sensors need several improvements, according to the Argonne scientists:

The ability to endure temperatures above 200 degrees C

The ability to endure radiation levels higher than 1000 rads per hour

A means of “harvesting” the energy inside the container,

Batteries that will power the sensors for more than 10 years, and

A way to wirelessly transmit the sensor data out of the cask.

The burnup rate of fuel rods is a measure of the energy extracted from a given amount of fuel, and is expressed in gigawatt-days per metric ton of uranium. The types of reactors in the U.S. have increased burn-up rates from 20-25 Gwd/MTU in 1970 to more than 45. The NRC has licensed storage casks at the higher burnup rates, but has not yet licensed their transportation.

Fuel rods may spend five years in pools of water before they cool enough to be loaded into dry storage casks. Currently, they are held in dry casks indefinitely while the U.S. pursues a permanent storage site. There are more than 1,200 dry casks holding spent fuel in the United States, according to Argonne, and the number is projected to pass 2,000 by 2020.

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Physicist know exactly what is happening inside the casks. They would never have been approved for use otherwise. As the waste decays the temperature and radiation levels will slowly drop over time forever.

They only need to look for leak done externally with a geiger counter.

Well aside from the article being non-factual, it pretty much represents the pro-nuke attitude of the people making billions from it.

“The project will enable us to equip a dry storage cask lid with advanced instrumentation so we can collect gas samples and monitor temperature and other variables while the fuel is cooling down,” said Neil Wilmshurst, EPRI’s vice president and chief nuclear officer.

Neil is not understanding that nuclear fuel doesn’t “cool down.” That’s like saying 1,500 degrees is 25% cooler than 2,000 degrees…true but, it still burns everything to a cinder and that’s after 250,000 years of “cooling!” The word “cool” is implied to mean, “Cool to the touch.” That is where the explanation of the “cooling” process stops.

The new fuels they are mixing together are even worst! That means, they will last longer! Hello? We don’t need the electricity produced in this way because, we don’t have manufacturing or a robust economy! If we really don’t need the power then, where is all this power being sold off to? The kicker is, NOT ONE nuclear power plant has ever turned a profit!

Consumer rates have always climbed up and out of sight! With all the technology required to create these “tea kettles”, how could they ever turn a profit except, for the companies building these power plants…BINGO! Right up until the nuke get’s started, billions are being made by these companies and then….everything turns into a consumer , “Black Hole”. Sucking money, lives, more money, politics, land, death and destruction for years 1,000s of years to come! What a concept!

The Cast System also represents man’s inability to deal with Reality. Once you create this “fuel”, it outlives everything around it. The Casts will deteriorate over centuries; the “advanced” instrumentation will become contaminated and antiquated over the centuries; nothing on Earth will contain this fuel until it becomes, “Cool.” Nothing can contain it.

Neil also doesn’t understand that he’ll be dead for 250,000 years and his “spent fuel” will still be killing everything it touches. Neil, you understand that? Did you get your degree in nuclear science or advanced keg partying?

Neil has a great job but, Neil is a very poor example of a human being. Neil is only thinking of himself and the chump-change he makes from his lies.

The wonderful thing about radioactive materials is that the hotter it is the shorter time it stays radioactive. The long lived isotopes have very little radiation. The very hot isotopes decay very quickly and become non-radioactive and cool.

Just think non-radioactive lead is poisonous forever. Highly-radioactive iodine-131 has a have life of 8 days.

In my opinion, used nuclear fuel is not waste, but just future fuel waiting to be recycled. They recycle it in France.

As for the cost of nuclear, compare France with Germany. France get almost all of their electricity from nuclear. Germany get the largest amount of electricity from coal, followed by Russian supplied natural gas. Electricity cost in France is $0.19 /kwh. In Germany it is $0.31 /kwh and rising.

This DOE EPRI “Demonstration Project” (EPRI High Burn-up Dry Storage Cask Research and Development Project) is not a solution. This project only tests high burnup fuel in existing cask technology (TN-32). The TN-32 cask is not even approved for high burnup fuel. It doesn’t include any research on finding better dry cask systems or better cladding for high burnup fuel. The devil is in the details. See the actual Demonstration Project details and related information on the report “High Burnup Nuclear Fuel – Pushing the Safety Envelope” http://sanonofresafety.org/2014/01/08/high-burnup-fuel-fact-sheet-2/

On March 6, 2014 10 am in DC, the NRC will have a meeting on this issue. http://meetings.nrc.gov/pmns/mtg?do=details&Code=20140362

High burnup fuel reacts with the protective Zirconium cladding to create hydrides. If exposed to oxygen, we could have a hydrogen explosion in the stainless steel canister. At minimum, high burnup fuel should be treated as damaged fuel and canned — each spent fuel assembly placed in a separate stainless steel canister. This provides a level of defense in depth that no longer exists with the failed cladding causes by high burnup fuel. Most fuel in spent fuel pools in the U.S. is high burnup fuel. Time is of the essence. This Demonstration Project is not a solution. http://sanonofresafety.org/nuclear-waste/

In the October 7, 2014 NRC meeting regarding this DOE/EPRI high burnup storage project, it was confirmed the lid monitoring for the project only applies to one existing TN-24 bolted lid cask and there are no plans for this project to develop internal monitoring for welded canisters (the main type used in the U.S.) or other casks with lid monitoring. Here’s a link to the slide presentation https://sanonofresafety.files.wordpress.com/2013/06/dominion-nrc-pre-sub-10-7-14-final.pdf